US President Bill Clinton was encouraged by his talks Tuesday with Israeli Prime Minister Ehud Barak on rescuing the Israeli-Palestinian negotiations but had no breakthroughs to announce on any of the stalled Mideast peace fronts, the White House said.

The two stretched a planned one-hour meeting into four at the White House for an exhaustive review of the talks between Israel, Syria, the Palestinians and on Israel's withdrawal from Lebanon, a senior administration official said on condition of anonymity.

Barak told reporters when he arrived at the White House Tuesday evening: "We have a variety of ideas to discuss about how to move to give new momentum and energy to the Palestinian track in order to live up to the timeline we have set."

But the official declined to say whether there was anything new from Barak, who Palestinian President Yasser Arafat has accused of foot-dragging on a framework agreement due May that is to produce a final accord in September.

"We are in the midst of dealing with the real heart and soul of the hardest issues ... and it is incumbent on both sides to come up with new ideas," said the official, adding: "There are gaps to be overcome."

A senior Israeli official described the talks as very good.

Quoted by Reuters as saying most of the four hours were devoted to the Palestinian track, the official added "the door is still open" on the Israeli-Syrian track.

On Lebanon, the official said Clinton expressed support for Israeli policy there.

Barak was holding talks with high-ranking US officials, Israeli and Palestinian negotiators were meeting just a few kilometers away at an American Air Force base in Bolling yesterday, discussing the final status agreement and the third West Bank pullback scheduled for mid-June under the interim agreement.

"So far, there are no results," Hasan Abdel Rahman, the PLO's representative in Washington, said of the Bolling negotiations. "Let's hope that will change," he told the Israeli daily Ha’aretz. Rahman added that the process would be shaken if the current round did not produce concrete results "and show seriousness on the part of the Israelis."

Arafat is due in Washington for talks on April 20 and the White House official said that the meeting combined "will give us a good sense of where we are."

"We have always played a constructive role in this (but) ... obviously it is up to the parties themselves to overcome these and reach agreement on these hard issues and there's no substitute for that," the official said – (Several Sources)